Macca enjoyed a cosy evening with married millionairess Nancy Shevell in a London hotel after spending the day in his bad-tempered divorce summit with Heather.

The secret rendezvous on October 11 came after hours of wrangling between Sir Paul, Heather and their legal teams as a High Court judge tried in vain to broker a divorce settlement.

Macca, 65, and American Nancy, 47, met two nights in a row at Blakes Hotel in Chelsea.

It is not known if he stayed the night. But a friend said: "I don't think they've spent the night together or anything like that. It's quite a romantic relationship. He is enjoying spending time in her company." The Mirror exclusively revealed yesterday that the ex-Beatle had shared tender kisses with super-rich Nancy during a three-day break in The Hamptons, the exclusive beach resort on Long Island, New York.

A friend said: "Heather demanded to know what the hell he was up to. She was furious because he hadn't told her about Nancy himself.

"She rang him and they had a huge row. She asked him how he thinks their daughter Bea would feel to see her dad and his new girlfriend splashed all over the newspapers."

But the friend claims Macca hit back - saying Heather could not point the finger after spending the past week making lurid public accusations about him.

The friend added: "After her behaviour last week, he told her she was hardly one to talk. He was utterly incredulous that she felt she could take the moral high ground after slagging him off on TV."

Other friends of Macca say he is "completely enthralled" with Nancy, who is married to wealthy lawyer Bruce Blakeman.

One said: "Paul's family are quite shocked he has got so close to Nancy, especially as she is a meat-eater.

"Let's not forget that Linda was a committed vegetarian and Heather is vegan. But that doesn't seem to be an obstacle. In fact, he is utterly enthralled by her.

"She is obviously a very beautiful woman but she is also intelligent and spirited. She is also very rich, so she's not after his money."

Macca's children Stella, James and Mary have nicknamed Nancy "Jackie O" after super-glamorous Jacqueline Onassis, the widow of President John F Kennedy.

The friend added: "The family have known her for years. Nancy and Bruce are old friends of Paul and Linda. The kids all call her Jackie O because she is so glamorous. She is used to the finer things in life.

"She changes all the linen in her house once a day because she likes it to look fresh and crisp.

"She is quite different from the kind of women he usually goes for.

"She is quite pampered and spoiled but feisty too.

"As a former member of one of the biggest bands in the world, he is the one used to being pampered and spoiled so it's a bit of a turnaround."

Nancy is also said to have been one of those who warned Macca not to marry Heather. The friend added: "She told him she didn't think Heather was right for him.

"It wasn't because she was after him or anything like that. It was just friendly advice because she knows him well and didn't believe Heather would make him happy."

Nancy, who has a teenage son, has recently stopped using her husband's surname. And both have been seen without wedding rings.

Sources close to Heather said she had no idea Macca was seeing Nancy - although she suspected he was in a relationship.

One friend said: "Her argument with Paul was the culmination of an incredibly stressful week for her.

"She's been on the TV and had had a lot of bad press as a result.

"She is also clashing with Paul on custody issues. And now she finds out he's got someone new in his life. She just boiled over."

Yesterday Macca refused to talk about Nancy as he returned to his London home. Mr Blakeman also declined to discuss his wife's weekend with McCartney.

Heather's US publicist Michele Blanc denied she was angry with Macca over Nancy.

She added: "Heather spoke to Paul and he swore to her it wasn't true. But even it was, she says that he is a free man and he can do what he wants. She is not distraught."